THIRD AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT


     This Third  Amendment  to  Amended  and  Restated  Credit  Agreement  (this
"Amendment")  is dated as of  December  15,  1997,  by and among  MAGNUM  HUNTER
RESOURCES, INC., a Nevada corporation (the "Borrower"), each Bank (as defined in
the Credit Agreement),  BANKERS TRUST COMPANY,  individually,  as administrative
agent (in such  capacity,  together with its  successors in such  capacity,  the
"Administrative  Agent"),  and as an issuing bank, and BANQUE PARIBAS,  a French
bank acting through its Houston Agency,  individually,  as collateral  agent (in
such capacity,  together with its successors in such capacity,  the  "Collateral
Agent"),  and as  documentation  agent  (in  such  capacity,  together  with its
successors in such capacity, the "Documentation Agent").

                                R E C I T A L S:

     WHEREAS,  the Borrower,  each Bank then a party, the Administrative  Agent,
the  Documentation  Agent,  and First Union  National Bank ("First  Union"),  as
collateral  agent and syndication  agent,  entered into that certain Amended and
Restated  Credit  Agreement  dated as of April 30,  1997 (the  "Original  Credit
Agreement")  pursuant  to which the Banks have agreed to make  revolving  credit
loans  available to the Borrower under the terms and provisions  stated therein;
and

     WHEREAS,  the parties to the Original Credit Agreement entered into a First
Amendment to Amended and Restated  Credit  Agreement,  Resignation of Collateral
Agent and  Appointment of Substitute  Collateral  Agent dated as of May 29, 1997
(the "First Amendment"); and

     WHEREAS, as of October 1, 1997, CIBC, Inc. ("CIBC") became a Bank under the
Original Credit Agreement as amended by the First Amendment; and

     WHEREAS, the parties to the Original Credit Agreement and CIBC entered into
a  Second  Amendment  to  Amended  and  Restated  Credit  Agreement  dated as of
September 30, 1997  (together with the First  Amendment and the Original  Credit
Agreement, the "Credit Agreement"); and

     WHEREAS, the Borrower has requested that the Banks and the Agents amend the
Credit  Agreement to (i) permit the  investment  in the  Marketing  LLC (defined
below)  in the form of cash and  promissory  notes;  (ii)  permit  certain  Debt
related to the Marketing LLC;  (iii) permit it to provide the limited  Guarantee
of certain  debt of the  Marketing  LLC;  and (iv) permit it to provide  certain
Trade Guarantees (defined below) of the Marketing LLC; and

     WHEREAS, the Banks and the Agents are willing to amend the Credit Agreement
as hereinafter provided; and

     WHEREAS,  the  Borrower,  the Banks and the  Agents now desire to amend the
Credit Agreement as herein set forth.

     NOW, THEREFORE, in consideration of the premises herein contained and other
good and  valuable  considerations,  the  receipt and  sufficiency  of which are
hereby acknowledged, the parties hereto agree as follows:

                                    ARTICLE I

                                   Definitions

     Section 1.1 Definitions.  Capitalized terms used in this Amendment,  to the
extent not  otherwise  defined  herein,  shall  have the same  meaning as in the
Credit Agreement, as amended hereby.


THIRD AMENDMENT TO CREDIT AGREEMENT - Page 1

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                                   ARTICLE II

                                   Amendments

     Section 2.1  Additional  Definitions.  Section 1.1 is amended by adding the
following definitions in alphabetical order:

                  "Marketing  Debt" means Debt of the  Borrower in an amount not
         to exceed  $4,000,000,  which  Debt  shall  consist  of the  Borrower's
         guaranty of Marketing  LLC's credit  facility.  Marketing Debt shall be
         characterized   as  Debt  of  the  Borrower   solely  for  purposes  of
         calculating the Borrower's Debt to  Capitalization  Ratio under Section
         11.4 hereof.

                  "Marketing  LLC" means the  limited  liability  company  being
         formed by the  Borrower or one of its  Subsidiaries  and NGTS that will
         assume all of NGTS's natural gas marketing operations.

                  "Marketing Note" means,  collectively,  one or more promissory
         notes in the amount of $2,000,000 issued by the Borrower and payable to
         NGTS,  which  promissory notes shall be payable in cash or common stock
         of the  Borrower,  at the sole  option of  Borrower.  The amount of the
         Marketing  Note  shall  not be  characterized  as Debt,  including  for
         purposes of computing the Borrower's Debt to Capitalization Ratio under
         Section 11.4 hereof,  so long as the Marketing Note is payable,  at the
         sole option of the Borrower, in common stock of the Borrower.

                  "NGTS" means Natural Gas Transmission Services, Inc.

                  "Permitted Investment in Marketing LLC" means an investment by
         the Borrower in Marketing  LLC, in an amount not to exceed  $4,500,000,
         which investment shall consist of (a) approximately  $2,500,000 in cash
         and (b) the Marketing Note.

                  "Trade  Guarantees"  means  Contingent  Liabilities in lieu of
         letters of credit  issued on behalf of the  Marketing LLC and for which
         the Borrower or one of its Subsidiaries  are severally,  or jointly and
         severally with one or more other Persons, or both, liable,  which Trade
         Guarantees  shall not exceed an  aggregate  of  $15,000,000.  Joint and
         several Trade  Guarantees  shall be subject to written  indemnification
         agreements,  in form and substance and from Persons satisfactory to the
         Agents,  in their  sole  discretion,  the  effect of which  shall be to
         reduce the liability of the Borrower.  Trade Guarantees will be treated
         as Debt  solely for the purpose of  computing  the  Borrower's  Debt to
         Capitalization   Ratio  and  solely  for  purposes  of  computing   the
         Borrower's Debt to Capitalization  Ratio under Section 11.4 hereof, the
         amount of joint and several Trade Guarantees that are  characterized as
         Debt in calculating such ratio shall be reduced by giving effect to the
         aforementioned written indemnification agreements.  Notwithstanding the
         foregoing,  the Majority  Banks shall at all times reserve the right to
         include the entire amount of joint and several Trade Guarantees, or any
         portion thereof,  as Debt in computing the ratio, based on such factors
         as the  Majority  Banks may from time to time deem  material,  in their
         discretion;  provided, however, that an Agent on behalf of the Majority
         Banks must give the Borrower  written  notice at least 90 days prior to
         the end of a  fiscal  quarter  in order  for any  amount  of joint  and
         several  Trade   Guarantees  in  excess  of  the   Borrower's  and  its
         Subsidiaries'  ratable share of such joint and several Trade Guarantees
         to  be  included  as  Debt  in  computing   the   Borrower's   Debt  to
         Capitalization Ratio for such fiscal quarter.

     Section 2.2 Amendment to Section 10.1.  Section 10.1 is amended by deleting
clause (d) in its entirety and substituting the following in lieu thereof:  "(d)
the Senior  Unsecured  Debt, the Marketing Debt, the Trade  Guarantees,  and the
Marketing Note."

     Section 2.3 Amendment to Section 10.3.  Section 10.3 is amended by changing
the reference to  "$1,500,000"  to $1,500,000  plus the Permitted  Investment in
Marketing LLC."



THIRD AMENDMENT TO CREDIT AGREEMENT - Page 2

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     Section 2.4 Amendment to Section 10.5.  Section 10.5 is amended by deleting
the  reference to  "1,500,000"  found in the fifth line thereof and inserting in
lieu  thereof  a  reference  to  "1,500,000  plus the  Permitted  Investment  in
Marketing LLC."

                                   ARTICLE III

                              Conditions Precedent

     Section 3.1 Necessary Documentation. This Amendment shall be effective when
the Agent shall have received this Amendment executed by all parties.

     Section 3.2 Borrower Covenant. The Borrower shall, within 30 days after the
date hereof, provide ----------------- the Agents with:

     (a)  Copies  of all  organizational  documents,  operating  agreements  and
regulations of the Marketing LLC; and

     (b) Any and all indemnification agreements relating to the Trade Guarantees
and  such  other  information  and  documents  relating  to the  indemnification
agreements as may be requested by the Agents, in their sole discretion.

     Section  3.3  Representations  and  Warranties.   All  representations  and
warranties contained in the Credit Agreement shall be true and correct on and as
of the date hereof with the same force and effect as if such representations and
warranties had been made on and as of such date.

     Section 3.4 Additional Documentation. The Agents shall have such additional
approvals,  opinions  or  documents  as the  Agents or their  counsel,  Winstead
Sechrest & Minick P.C., may reasonably request.


                                   ARTICLE IV

                                  Miscellaneous

     Section  4.1  Ratifications,  Representations  and  Warranties.  Except  as
expressly modified and superseded by this Amendment, the terms and provisions of
the Credit Agreement and the other Loan Documents are ratified and confirmed and
shall  continue in full force and effect.  The  representations  and  warranties
contained  herein and in all other Loan Documents,  as amended hereby,  shall be
true and correct as of, and as if made on, the date hereof.  The  Borrower,  the
Banks and the Agents  agree that the Credit  Agreement  as amended  hereby shall
continue to be legal,  valid,  binding and  enforceable  in accordance  with its
terms.

     Section 4.2 Reference to the Credit Agreement.  Each of the Loan Documents,
including the Credit  Agreement and any and all other  agreements,  documents or
instruments now or hereafter executed and delivered pursuant to the terms hereof
or pursuant to the terms of the Credit  Agreement as amended hereby,  are hereby
amended so that any  reference in such Loan  Documents  to the Credit  Agreement
shall mean a reference to the Credit Agreement as amended hereby.

     Section 4.3 Expenses. The Borrower agrees to pay on demand all expenses set
forth in Section 14.1 -------- of the Credit Agreement.

     Section 4.4 Severability. Any provisions of this Amendment held by court of
competent  jurisdiction  to be  invalid  or  unenforceable  shall not  impair or
invalidate  the  remainder of this  Amendment  and the effect  thereof  shall be
confined to the provisions so held to be invalid or unenforceable.



THIRD AMENDMENT TO CREDIT AGREEMENT - Page 3

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     Section 4.5  Applicable  Law. This  Amendment and all other Loan  Documents
executed  pursuant  hereto shall be governed by and construed in accordance with
the laws of the State of New York.

     Section 4.6  Successors  and  Assigns.  This  Amendment is binding upon and
shall inure to the benefit of the Banks,  the Agents and the  Borrower and their
respective successors and assigns.

     Section 4.7  Counterparts.  This  Amendment  may be executed in one or more
counterparts,  each of which when so executed  shall be deemed to be an original
but all of  which  when  taken  together  shall  constitute  one  and  the  same
instrument.

     Section 4.8 Headings. The headings, captions, and arrangements used in this
Amendment are for convenience  only and shall not affect the  interpretation  of
this Amendment.

     Section 4.9 NO ORAL AGREEMENTS.  THIS AMENDMENT AND ALL OTHER  INSTRUMENTS,
DOCUMENTS AND AGREEMENTS EXECUTED AND DELIVERED IN CONNECTION HEREWITH REPRESENT
THE FINAL AGREEMENT BETWEEN THE PARTIES, AND MAY NOT BE CONTRADICTED BY EVIDENCE
OF PRIOR,  CONTEMPORANEOUS  OR SUBSEQUENT ORAL  AGREEMENTS  BETWEEN THE PARTIES.
THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

                [Balance of this page intentionally left blank.]


THIRD AMENDMENT TO CREDIT AGREEMENT - Page 4

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         EXECUTED as of the day and year first above written.

BORROWER:

MAGNUM HUNTER RESOURCES, INC.


By:
     Name:
     Title:


ADMINISTRATIVE AGENT:

BANKERS TRUST COMPANY



By
     Name:
     Title:

DOCUMENTATION AGENT
AND COLLATERAL AGENT:

BANQUE PARIBAS



By:
     Name:
     Title:


                            - and -


By:
     Michael H. Fiuzat
     Vice President

ISSUING BANK:

BANKERS TRUST COMPANY


By
     Name:
     Title:



THIRD AMENDMENT TO CREDIT AGREEMENT - Page 5

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                                                     BANKS:

                                 BANQUE PARIBAS


                                                     By:
                                      Name:
                                     Title:

                                     - and -

                                                     By:
                                                          Michael H. Fiuzat
                                                          Vice President


                                                     BANKERS TRUST COMPANY


                                                     By:
                                      Name:
                                     Title:


                                   CIBC, INC.


                                                     By:
                                      Name:
                                     Title:





THIRD AMENDMENT TO CREDIT AGREEMENT - Page 6

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                          ACKNOWLEDGEMENT BY GUARANTORS


        Each of the undersigned  Guarantors hereby (i) consents to the terms and
conditions of the Amendment, (ii) confirms and ratifies the terms of the Amended
and Restated Subsidiary Guaranty, (iii) acknowledges and agrees that its consent
is not required for the  effectiveness  of the Amendment and (iv) represents and
warrants that (a) no Default or Event of Default has occurred and is continuing,
(b) it is in full compliance with all covenants and agreements  pertaining to it
in the Credit Documents and (c) it has reviewed a copy of the Amendment.

              Executed as of December 15, 1997.


                                                GUARANTORS:

                                                HUNTER GAS GATHERING, INC.
                                                GRUY PETROLEUM MANAGEMENT CO.
                                                MAGNUM HUNTER PRODUCTION, INC.
                                                CONMAG ENERGY CORPORATION
                                                RAMPART PETROLEUM, INC.


                                       By:
                                      Name:
                                     Title:




THIRD AMENDMENT TO CREDIT AGREEMENT - Page 7